Technical Field
Embodiments of the present invention relate to the field of touching technologies, and particularly, to an in cell touch panel and a method for driving the same, and a display device.
Description of the Related Art
With the rapid development of the display technology, touch panel has been gradually spread throughout the life of people. Nowadays, according to structure and component, the touch panels are categorized into: Add on Mode Touch Panel, On Cell Touch Panel, and In Cell Touch Panel. As to the Add on Mode Touch Panel, the touch screen and the liquid crystal display (LCD) are manufactured separately, and then they are assembled together to form a liquid crystal display having a touch function. The Add on Mode Touch Panel has disadvantages of relatively higher manufacture cost, relatively lower light transmittance and relatively greater thickness of the module. However, as to the In Cell Touch Panel, touch electrodes of the touch panel are embedded inside the liquid crystal screen, which decreases thickness of the module, as well as greatly reduces manufacture cost of the touch panel, so it is favored by the major panel manufacturers.
At present, conventional in cell touch panel mainly achieves detection of positions of finger's touch operations by means of utilizing principle of mutual capacitance. In a specific implementation, it is obtained by direct additions of the touch scanning lines and the touch sensing lines on conventional thin film transistor (TFT) array substrate; that is, on a surface of the TFT array substrate, two layers of transparent conductive electrodes (generally, strip-shaped indium tin oxides (ITO) electrodes), which are intersected with each other, are formed and they are used as the touch driving lines and the touch sensing lines of the touch panel, and a sensing capacitor is formed at a place where the two layers of ITO electrodes are intersected with each other. It has the following working process. When touch driving signal is applied on the ITO electrodes serving as touch driving lines, voltage signal coupled to the touch sensing lines through the sensing capacitor is detected. During this process, when a human body gets into contact with the touch panel, an electrical field from the human body will act on the sensing capacitor and make value of capacitance of the sensing capacitor change, so as to vary the voltage signal coupled to the touch sensing lines. As a result, position of the touch point will be determined in accordance with variation of the voltage signal.
In a structural design of the abovementioned conventional in cell touch panel, new layers are required to be added onto traditional TFT array substrate, which results in addition of additional process in the manufacturing of the TFT array substrate, as a result, the manufacture cost is increased, and it is not advantageous to improvement of the manufacture efficiency.